Craniofacial synostosis (Craniosynostosis)

Definition

Classification

1. Primary craniosynostosis

• Usually involves a single suture.
• Most common: sagittal synostosis.

• Multiple sutures may be involved.
• Often associated with mutations involving fibroblast growth factor receptor pathways.
• Common syndromes:
  • Crouzon syndrome
  • Apert syndrome
  • Pfeiffer syndrome
  • Muenke syndrome
  • Saethre-Chotzen syndrome

2. Secondary craniosynostosis

• Microcephaly
• Metabolic bone disease
• Haematological disorders
• Drug exposure
• Treated hydrocephalus or other causes of reduced brain growth

Types and characteristic deformities

Clinical features

Local craniofacial findings

• Abnormal skull shape from birth or progressing in infancy
• Palpable hard ridge over a fused suture
• Absent or early closure of fontanelle
• Frontal, parietal, or occipital bossing
• Facial asymmetry
• Orbital dystopia, proptosis, hypertelorism or hypotelorism
• Midface hypoplasia in syndromic cases

Features of raised ICP

• Irritability, persistent vomiting, headache in older children
• Bulging fontanelle may occur, although it can be absent
• Papilloedema
• Visual deterioration or optic atrophy
• Developmental delay
• Sleep disturbance

Associated abnormalities in syndromic disease

• Airway obstruction and obstructive sleep apnoea
• Hearing loss and recurrent otitis media
• Hydrocephalus or Chiari malformation
• Dental malocclusion
• Limb anomalies, especially syndactyly in Apert syndrome
• Developmental and behavioural difficulties

Differential diagnosis

Diagnostic and management flowchart

Infant with abnormal head shape / facial asymmetry
                    │
                    ▼
Detailed history and examination
- Onset at birth, progression, sleeping position
- Head circumference and developmental assessment
- Palpate sutures/fontanelles
- Look for syndromic features, airway and eye problems
                    │
                    ▼
Is craniosynostosis clinically suspected?
          │                            │
         No                           Yes
          │                            │
          ▼                            ▼
Consider positional              Urgent referral to a
plagiocephaly, torticollis,      multidisciplinary craniofacial team
or other causes                         │
                                       ▼
                         Ophthalmology + genetics assessment
                         Hearing, airway and developmental review
                                       │
                                       ▼
                     Imaging when required for confirmation/
                     operative planning:
                     low-dose CT with 3-D reconstruction
                     ± ultrasound / MRI for brain, hydrocephalus,
                     Chiari malformation or venous anatomy
                                       │
                                       ▼
          ┌─────────────────────────────────────────────┐
          │ Single-suture, mild, no functional problem   │
          │ versus multisuture/syndromic/raised ICP      │
          └─────────────────────────────────────────────┘
                     │                         │
                     ▼                         ▼
          Individual surveillance        Early cranial vault expansion/
          or planned correction          remodelling as indicated
                     │                         │
                     └───────────────┬─────────┘
                                     ▼
                         Long-term multidisciplinary follow-up:
                         head growth, skull shape, vision/ICP,
                         development, hearing, airway, dentition

Management

1. Principles

1. Allow adequate intracranial volume and prevent or treat raised ICP.
2. Correct cranial and facial deformity.
3. Preserve vision and manage orbital complications.
4. Treat airway, hearing, dental, developmental, and psychosocial problems.
5. Provide genetic diagnosis and family counselling.

2. Initial assessment and investigations

• Document head circumference, skull shape, growth, and developmental status.
• Photograph or use three-dimensional surface imaging where available.
• Ophthalmological assessment for papilloedema, optic atrophy, strabismus, and exposure keratopathy.
• ENT/audiology assessment, particularly in syndromic children.
• Assess feeding, airway obstruction, and obstructive sleep apnoea. Polysomnography is useful if sleep-disordered breathing is suspected.
• Clinical geneticist review and molecular testing in multisuture disease, syndromic features, or positive family history.
• Low-dose CT with three-dimensional reconstruction is used selectively to confirm suture fusion and plan surgery.
• MRI brain and cervicomedullary junction when hydrocephalus, Chiari malformation, intracranial anomaly, or venous abnormality is suspected.

3. Surgical management

Indications

• Significant cranial deformity
• Raised ICP or restricted intracranial volume
• Progressive deformity
• Threat to visual function
• Multisuture or syndromic craniosynostosis
• Severe orbital, facial, or airway consequences

A. Endoscopic strip craniectomy

• Minimally invasive removal of the fused suture.
• Best suited to selected infants presenting early, often in the first few months of life.
• Usually followed by postoperative moulding helmet therapy.
• Commonly considered for early sagittal, metopic, and selected unilateral coronal/lambdoid cases.

B. Open cranial vault remodelling

• Open strip craniectomy with cranial vault expansion and reshaping.
• Used when presentation is later, deformity is severe, multiple sutures are involved, or an endoscopic approach is unsuitable.
• May include fronto-orbital advancement for coronal or metopic deformity.
• Usually performed during infancy, with timing tailored to the affected suture, severity, surgical technique, and centre protocol.

C. Procedures for syndromic disease

• Posterior cranial vault expansion
• Fronto-orbital advancement
• Midface advancement, for example Le Fort III or monobloc advancement
• Management of hydrocephalus, Chiari malformation, and severe proptosis
• Tracheostomy or airway surgery in severe obstructive sleep apnoea

4. Non-surgical and supportive treatment

• Reassure and educate parents.
• Treat positional plagiocephaly with repositioning, physiotherapy for torticollis, and selected helmet therapy, not cranial surgery.
• Nutritional and feeding support where needed.
• Hearing aids or ventilation tubes for recurrent middle-ear disease.
• Continuous positive airway pressure or airway surgery for obstructive sleep apnoea when indicated.
• Speech, language, occupational, developmental, and psychological support.
• Orthodontic treatment and dental surveillance.

5. Follow-up

• Head circumference and skull shape
• Developmental progress and school performance
• Headache, vomiting, irritability, and sleep symptoms
• Ophthalmic examination for papilloedema and optic nerve changes
• Hearing and middle-ear disease
• Airway and sleep apnoea
• Dental development and malocclusion
• Need for repeat cranial or facial surgery

Complications

• Raised ICP and visual loss
• Hydrocephalus
• Chiari malformation
• Venous sinus abnormalities
• Neurodevelopmental and learning difficulties
• Obstructive sleep apnoea
• Hearing impairment
• Persistent or recurrent cranial deformity
• Blood loss, infection, dural tear, and need for reoperation after surgery

Conclusion